/*
 * Copyright 2010 Google Inc.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package java.io;

public abstract class InputStream {
  public abstract int read() throws IOException;
  
  public int read(byte[]buf, int start, int len) throws IOException {
    
    int end = start + len;
    for (int i = start; i < end; i++) {
      int r = read();
      if (r == -1) {
        return i == start ? -1 : i - start;
      }
      buf[i] = (byte) r;
    }
    return len;    
  }
  
  public int read(byte[] buf) throws IOException {
	 return read(buf, 0, buf.length);
  }
  
  public void close() throws IOException {
    
  }
}
